Hydrangea plant named ‘BC7.3’

ABSTRACT

A new and distinct cultivar of  Hydrangea macrophylla  (Thunb.) named ‘BC7.3’ originated as a controlled cross between varieties. The cultivar ‘BC7.3’ can be blue or red depending on the acidity of the soil and the presence of aluminum. The variety ‘BC7.3’ has relatively compact, attractive inflorescences with relatively small sepalous florets, distinct sepal pigmentation and good commercial characteristics. When grown in the presence of aluminum, the upperside of the sepals is primarily R.H.S. 94 A (violet-blue group) and 86 B (violet group), the underside of the sepals is R.H.S. 93 D (violet-blue group) and 86 C violet group).

Botanical classification: Hydrangea macrophylla (Thunb.) ‘BC7.3’.

Variety denomination: ‘BC7.3’.

BACKGROUND OF THE INVENTION

This invention relates to a new and distinct cultivar of the Saxifragaceae family. The botanical name of the plant is Hydrangea macrophylla (Thunb.) ‘BC7.3’.

The new cultivar originated as a seedling from a controlled cross between a commercial variety known as ‘Venedig’ to the inventor which may be the subject of U.S. Plant Pat. No. 10,928 and registered as ‘Venice Raven’. ‘Venedig’ was the seed parent and the unpatented variety ‘LK49’ was the pollen parent. ‘LK49’ is relatively compact plant with wiry stems, relatively small leaves, relatively small sepalous florets, and inflorescences that are resistant to being damaged by conditions in commercial coolers.

The variety ‘BC7.3’ has compact, attractive inflorescences with relatively small sepalous florets, attractive sepal pigmentation and good commercial characteristics, including the characteristic that the sepals are highly resistant to osmotic pressure. The variety ‘BC7.3’ has pigmented sepals, and is preferably grown in soil conditions treated with aluminum to produce blue pigmentation. The color of the sepals changes as the plant ages. Below is a table comparing the new variety to similar varieties. Blooms approximately 1 month earlier than similar varieties grown under commercial conditions for sale as a decorative potted plant. The new variety is generally taller than its parents and the stems need to be staked. ‘Venedig’ and the new variety have similarly sized inflorescences.

TABLE 1 New Variety Patented Variety ‘BC6.1’ ‘BC7.3’ U.S. Plant Pat. No. 23,757 Leaf size 9 cm × 15 cm 12 cm wide × 15 cm long Plant height 16″ in 6″ pot. 15″ in 6″ pot. Stem strength Stems are strong but Stems are strong but benefit benefit from being staked. from being staked. Sepal Upper side of sepals is Upper side of sepals is R.H.S. Pigmentation R.H.S. 94 A (violet-blue 86 A (violet group); Under side group) to 86 B (violet of sepals is R.H.S. 88 D group); Under side of (violet group) sepals is R.H.S. 93 D (violet group) to 86 C (violet group). Sepalous 50 mm 60 mm to 70 mm Floret Size Commerical variety ‘Venedig’ U.S. Plant Pat. No. 18,593 which may be U.S. Plant Pat. ‘True Blue’ No. 10,928 ‘Venice Raven’ Leaf size Unknown 9 cm wide × 15 cm long- observed controls grown alongside new variety Plant height Unknown 12″ in 6″ pot-observed controls grown alongside new variety. Stem strength Strong Strong-observed controls grown alongside new variety Sepal Both sides of sepalsa are Upper side of sepals is R.H.S. Pigmentation R.H.S. 100 D (blue 84 A (violet group). group). Under side of sepals is R.H.S. 85 A (violet group) observed controls grown alongside new variety. Sepalous 50 mm to 60 mm 70 mm - observed controls Floret Size grown alongside new variety

The new cultivar ‘BC7.3’ has been successfully asexually reproduced under controlled environmental conditions at a nursery in Half Moon Bay, Calif. under the direction of the inventor with its distinguishing characteristics remaining stable.

Asexual reproduction was first accomplished when vegetative stem cuttings were taken from the initially selected plant. Examination of asexually reproduced, successive generations grown in Half Moon Bay, Calif. show that the combination of characteristics as herein disclosed for ‘BC7.3’ remains firmly fixed through.

DESCRIPTION OF THE DRAWINGS

The accompanying drawings consist of color photographs that show the typical plant form, including the inflorescence, foliage, and sepals.

FIG. 1 is a view of the entire plant showing its form, growth habit, dark green foliage, inflorescence, and the color of its sepals.

FIG. 2 is a view of the entire plant showing its form, growth habit, dark green foliage, inflorescence, and the color of its sepals.

FIG. 3 is a close-up view of the adaxial surface of a mature leaf.

FIG. 4 is a close-up view of the base of the stem.

FIG. 5 is a close-up view of the upper side of a panicle of the new variety.

FIG. 6 is a close-up view of the center of a panicle of the new variety.

DESCRIPTION OF THE NEW PLANT

The plants shown in the figures are approximately 51 weeks old. The plant started out as cuttings, taken from the stem of a grown plant. The cuttings were placed in a pot and the soil was periodically treated with aluminum to produce blue pigmentation. The plant was pinched early to promote lateral branches.

‘BC7.3’ has not been observed under all possible environmental conditions. The phenotype may vary significantly with variations in environment such as temperature, light intensity and day length. Color determinations were made with The Royal Horticultural Society (R.H.S.) Colour Chart, in association with the Flower Council of Holland, located in Lieden.

THE PLANT

-   Origin: Controlled cross. The new cultivar originated as a seedling     from a controlled cross between the commercial variety known to the     inventor as ‘Venedig’ and which may be ‘Venice Raven’, U.S. Plant     Pat. No. 10,928, which was the seed parent and the unpatented     variety ‘LK49’ which was the pollen parent. -   Form: Upright, compact shrub. A typical plant with a mature     inflorescence that is ready for sale is approximately 16″ high and     has a diameter of 16″ when grown in a 6″ pot with appropriate soil     amendments. Plants typically have 3 to 4 stems with one     inflorescence between each stem. -   Growth: Upright, vigorous growth habit. Inflorescence is large. The     plant branches easily with shoots forming at the base of the plant.     Lateral branches are similar in appearance and form to the main     stems. -   Stems: Lenticels are present. Lenticels are R.H.S. 86 A (violet     group) and are 1 to 2 mm long. The surface of young stems is     glabrous. Stems become woody as they age. The color of typical young     stems and young lateral branches is R.H.S. 144 A (green group). The     older portions of the stems are R.H.S. 199 B (grey-brown group)     Younger portions of the stems are 5 to 7 mm in diameter. Older     portions of the stems are 5 to 7 mm in diameter. -   Foliage: Abundant. Leaves are opposite on stem and lateral branches.     -   -   Shape of leaf.—Elliptic with acute base and apex. Margins             are serrate.         -   Texture.—Glabrous; veins dominate on the underside of the             leaf and are sunken on the upper leaf surface.         -   Color.—Mature leaves have an upper side that is R.H.S. 147 A             (yellow-green group), and an under side that is R.H.S. 138 B             (green group). Leaves are pinnately veined. The midvein and             veins branching off the midvein are large and prominent on             the underside of the leaves. Veins are R.H.S. 144 D             (yellow-green group). Leaves are as wide as 9 cm and 15 cm             long. Petioles are smooth and 2.0 cm long and 4 mm wide.             Petioles are R.H.S. 144 D (yellow-green group).

BUDS

-   Form: Globose with 4 to 5 connate, elliptic, smooth petals. Most     buds, whether they will mature into sepalous or non-sepalous     florets, have 4 petals. Buds in the center of the inflorescence are     non-sepalous. The majority of buds will develop into sepalous     florets. They are approximately 1 mm by 1 mm when very young. Buds     can be 3 mm in diameter and still unopened. Color of buds is R.H.S.     100 C (blue group). -   Aspect: Unopended petals encasing buds are smooth. -   Arrangement: Borne on branched panicles.

INFLORESCENCE

-   Form: Paniculate. Terminal. As many as 100 individual flowers     (florets) per inflorescence. Both sepalous florets and non-sepalous     florets borne on same panicle, with many more non-sepalous florets     than sepalous florets. Flowers do not produce a fragrance. The     peduncle for the inflorescence is strong and upright. Very few     non-sepalous florets developing early on cymes that are later hidden     by sepalous florets. Florets, both sepalous and non-sepalous, have     anthers and style. Inflorescences are long-lasting, changing color     as they age. -   Size of inflorescence: Compact and globose. Individual inflorescence     size is dependent on the number of florets. A typical inflorescence     can grow as large as 7″ in diameter, and 4″ high. -   Shape: Clusters of numerous small florets; sepalous florets overlap     one another. Sepals are persistent. -   Appearance: Showy.

FLORETS

-   General: The non-sepalous florets at the center of the inflorescence     open first. Sepalous and non-sepalous florets are perfect and     complete.     -   -   Corolla.—Generally, for both sepalous and non-sepalous             florets there are 4 petals which fall off as flower matures.             Petals are typically 4 mm long and 3 mm wide. Lenticels that             are very small are present on pedicels of both sepalous and             non-sepalous florets. Pedicel of both sepalous and             non-sepalous florets are primarily 95 C (violet-blue group)             when inflorescence is ready for commercial sale.             Non-sepalous florets typically lack petals and are 3 mm in             diameter. Color of petals before they fall off are R.H.S.             100 C (blue group). -   Stamens: 8 stamens, for both sepalous florets and non-sepalous     florets. Pollen is R.H.S. 158 C (yellow-white group). Plant produces     abundant pollen. Filament is approximately 3 mm long. Filament is     R.H.S. 155 C (white group). Anther is 1 mm long and is regular and     basally attached. -   Stigma: Two to three style each, although most florets have two     style, for both sepalous florets and non-sepalous florets. Each     style has one stigma. Style is typically 1 mm long. For young     inflorescences ready for commercial sale style is R.H.S. 155 D     (white group) and stigma is R.H.S. 155 D (white group). -   Ovary: Ovary is partially inferior, for both sepalous florets and     non-sepalous florets. -   Sepalous florets:     -   -   General.—Veins dominate on the underside of the sepals.         -   Number of sepals.—4 or 5 sepals per floret, usually 4.         -   Aspect of sepals.—Smooth and glaucescent.         -   Shape of sepals.—Reniform with acuminate apex. Edges are             entire, but with much crenation.         -   Size of sepals.—As the florets mature, the sepals enlarge             and overlap each other more and more, until, often, there is             no space between the sepals when the petals of the florets             open. Sepals at maturity are typically 3.0 cm long and 4.0             cm wide. Flowers are typically 5 cm in diameter. The upper             sides of the sepals are primarily R.H.S. 94 A (violet-blue             group) and 86 B (violet group) and the under sides are             primarily R.H.S. 93 D (violet-blue group) and R.H.S. 86 C             (violet group). Blue pigmentation develops at the tips of             the sepals and travels inward towards the base of the             sepals. Color of the sepalous florets changes as the             inflorescence ages. The upper sides of older sepals are             primarily R.H.S. 77 A (purple group) and 93 D (violet             group), becoming R.H.S. 138 A (green group). -   Fruit: None. -   Disease and pest resistance: Unknown. -   Other distinguishing characteristics: The sepals of the new variety     are highly resistant to osmotic pressure which means the blooms age     well and can be sold as “vintage” varieties. Plants are typically     held for another 10-12 weeks after the blooms reach maturity before     they are sold. During the holding period, because the sepals are     resistant to osmotic pressure, the inflorescences do not have to be     cleaned as often to remove dessicated florets and sepals. 

I claim:
 1. A new and distinct Hydrangea macrophylla plant named ‘BC7.3’ substantially as herein shown and described. 